Whether an individual’s skin responds to exposure to sun with tanning or with a sunburn may, at least in part, be determined by variation in certain genomic regions (“loci”), reports a paper published in Nature Communications this week. This genome-wide association study (GWAS) expands on previous work by identifying additional genetic loci that may be associated with tanning response in a population of European ancestry.

To better understand how the genetic make-up of an individual determines their response to sun exposure, Mario Falchi and colleagues analysed genetic variation in participants who had self-reported to never tan or only occasionally tan and burn (46,768) and those who do tan without burning (74,528), which was followed up in a replication sample of 55,382 individuals. This revealed variation at ten genetic loci that had not been associated with tanning response previously. The researchers further find that some of the variants at the AGR3/AHR locus associated with lower tanning ability might also increase the risk of skin cancer.

The authors note that the findings are based on self-reporting (i.e. questionnaire responses) for tanning and for skin cancer, which might be prone to reporting bias, and further studies are required to confirm any functional role the genetic variants identified may play in these processes.